Efficiently and accurately reading from, and writing to, electronic tags, e.g., radio frequency identification (“RFID”) tags, attached to merchandise, packaging or other assets that may be located in a building such as on the floor of a retail store, stored in a retail backroom or warehouse, is an important aspect of supply chain and inventory management.
In traditional inventory management systems, such as warehouse management operations, bar codes are attached to the loads, merchandise, and packaging or to mark specific locations. In a typical example of such a system, the operator uses a hand-held bar code scanner to read the bar code on the loads and, in some cases, on the stock locations. Such a system can be difficult to completely implement, due partly to the need for direct line of sight, close proximity, and proper alignment between the scanner and barcodes. Certain locations, for example high storage shelves and loading docks, often are particularly difficult places for using bar codes because of the need for close proximity between the codes and the reader. As a result, loads in those areas are often visually identified instead.
RFID tag systems have been proposed for use in inventory tracking. RFID tags typically include an integrated circuit (“IC”) that is operatively coupled to an antenna of the tag. The tag may also be active and have a battery, or it may be passive and have no battery and obtain operating energy from an external reader. RFID tags without batteries may be preferred for applications in which lower cost is a dominant factor, and RFID tags with batteries may be preferred for applications in which a longer read range is preferred. Either or both may be used in conjunction with the present invention.
In some applications, such as RFID, there is a need to not only read from the tags but also to program them. For example, there are some inventory tracking systems that deploy fixed RFID readers at various locations to detect RFID-tagged items when these RFID-tagged items are positioned near the RFID reader-equipped locations. An RFID reader is a device that is capable of not only reading from the tags, but also capable of programming, e.g., writing data, to the tags. The installation of RFID readers at every inventory location, however, is not cost effective. For example, there are the additional costs for the infrastructure to support the deployment of the fixed RFID readers. These costs can include, the cost of the additional tag readers, antennas, cabling required to connect all the fixed RFID readers and antennas, and the additional power drops for fixed RFID readers and antennas.
Some attempts to resolve the issues of cost and coverage include the use of “ad hoc” carts which are not specifically designed with sufficient flexibility to meet the customer needs of reading and writing to RFID tags/labels from ground level to elevated heights. Many of these “ad hoc” carts are not self-contained, or the carts must be tethered to a power source for operation, which greater limited their mobility.
In other attempts, retailers have also “rigged” a cart, e.g., sometimes even a shopping cart, by placing both merchandise pricing equipment, and RFID reader and antenna hardware on the cart and pushing it around the retail floor or storeroom. These “rigged” carts are typically unwieldy and hard to push due to the uneven weight distribution of the equipment placed in them. In addition, these “rigged” carts are often difficult to maneuver as these carts may be large and many times are too large to fit down aisles without interfering with shopping customers. Because these homegrown systems are not intended for mobile operation, the read range is also limited as such RFID tags at high locations may not be read accurately, if at all.
Others have tried to address just the RFID hardware aspects by dedicating a cart to RFID. The “RFID-dedicated” carts are typically low to the ground, e.g., often less than 3.5 feet tall, and the RFID hardware is mounted on the cart, typically by using various clamps, tie-wraps and tape. The fixed antennas are mounted on the cart and can be up to 7 feet in length, which still causes problems with overall weight and maneuverability. These “RFID-dedicated” carts may also become unbalanced with a tendency to tip over. These “RFID-dedicated” carts are also often distracting to customers. Additionally, retailers still have to return to the same merchandise with another cart to address other activities, e.g., sales displays and pricing activities. Even with such unwieldy antennas, these carts still may have limited read ranges.
A system is therefore needed that allows for the efficient interaction, e.g., reading and writing, with electronic tags on the products and items that better addresses issues of cost, complexity, safety, size, mobility, and ease of use.